Flotation concentrating machine



Feb. 2 1932. w, PUDJAN 1,843,696

FLOTATIQN CONCENTRATING MACHINE Filed Feb. 8, 1928 2 Sheets-Sheet 1 lm'lunmu N Jim/7m.

H. W. PUDAN FLOTATION CONCENTRATING MACHINE Feb. 2, 1932.

Filed Feb. 8, 1928 2 Sheets- -Sheet 2 ?atented Feh. 2, 1932 I unrrsn srA'rs PATENT orrics mR-BERT WATKOUG H OTB L08 AHG-ELES, CALIFORNIA, ASSIGNGB T0 SOUTH- WESTERN ENGINEERING- OQMPANY, 01 L08 ANGEBES, CALIFORNIA, A CORPORATION" GE" GALIFQBNIA.

rno'rn rron oononnrnsrrn'o monmn Application filed rebmer e, 1828. Serial nonsense.

and secreted to form n, velue-cerrying froth which is collected.

Qne object of my invention is to provide I n so. erior method and means for supplying eir :or the flotation end s more economical method and efiicient moons for agitating the pulp in the flotation machine. t is also on object of the invention to provide means which will closely regulate the amount or air supplied and the extent of the agitation 'so as to ohtsin the most eficient conditions.

Generally speaking, there are two types of.

flotation machines, one known es the sgitetor 2pc sndthe other as the sir blanket type.

t the present ste e of development of the flotation art, neit or type is particularly suited to flotation conditions. In the egitetor type, sir is introduced into the ulp by a heater or by e vortexection, on in the air blanket type the air is forced through the meshes of the blanket and is thereby dis persed through the pulp. But the. a itetor machine agitetes, and disrupts the pn p too much, while with the other type, although a nice float is made, the blankets plug up elgogether too fest end their eficiency is soon t l-l It is well established that finely divided air and a. comparatively large amount of it under at least a slight pressure, is the most important feature in flotation. Also, my experience has shown nie that some mechsnicol agitation is necessary, largely to prevent the settling out of the heavier particles. Therefore l have devised s machine which cornhines these two functions and accomplishes both results in s. new and highly practical and efficient manner. With this machine I can easily and economically furnish to the pulp all the air that can ever be used, end at t e some time produce sufficient egitetion to prevent settling. Since 1 con make the air needed and give the sgitetion re 'uired within very close range of the most e cient conditions, I can operate my machine at e. minimum expenditure of power.

Briefly stated, the invention resides broad ly in n vertically reciprocatin aeratingagitetor which performs the com ined functions of an air pump and s mechenicsl ulpagitston, In a referred form this evice comprises a. horizontsl id or perforated plate which-nets es s pu p cgitctor end sir distributor, said grid being carried upon the lower end of a hollow stem through which air enters and through the medium of which the device is vertically reciproceted. The reciprocation serves to pump sir into the pulp, a valve being provided in connection with said hollow stem and preferably at the lower end thereof, said valve opening on such upstroke to permit air to be sucked in through the hollow stem by the tendency toword creation of a vacuum therebeneeth, end closing on each downstroke to prevent return of the air and to insure mixing of the sirwith the pulp. Eeciprocation 1s repid and results in breaking up all of the large air bubbles end dissipating the air in fine streams through the pulp so that the finely difiused air may readily nttsch itself to the small metallic particles. Not onl is the air thus properl conditioned end 'istrihut ed, but the pulp 1s suficiently agitated to prevent settling. Thus agitation is under control, settling is under control, and, since sulficient air is furnished in proper condition, efiicient flotation results.

A plurality of these eereting ugitetors may be placed in separate cells feeding from. one to another in series, or arranged in both persllel end seriesf-end preferehly on ugiteting ci'rculetor will be interposed hetween the cells in the series. The circuletor is in the form of on egitnting pump coin rising e reciproeating horizontally dispose grid mounted on e hollow vertically reciprocating stern heving e valve which opens on the downstrolie end. closes on the upstroke so no to force it streets of pulp up through the stem end discharge it ed scent the overflow to the next cell, err-ch circuletor being in on independent cornpurt ment which receives from. the bottom of one cell and feeds by overflow to the top of the usual iform (not tures of novelty as above pointed out but also in such other novel features and combinations as may be elsewhere herein set out.

In the accompanying drawings wherein certain specific embodiments of the invention are disclosed by way of illustration:

Fig. 1 is a plan view with parts broken away of a mo ification wherein each aerating-agitator is disposed in a separate cell, the cells being arranged in series, and compartments being'arranged between adjacent cells and containing circulating agitators for insuring proper circulation through the flotation unit.

Fig. 2 is a longitudinal section taken on line -5 of Fig. 4:.

Fig. 3 is a vertical section through one of the aerating agitators.

Fig. 4: is a plan view of the grid of such aerating agitator.

Fig. 5 is a plan View of a modified form of grid or plate.

Fig. 6 is a vertical section through one of the agitating circulators; and

Fig. 7 indicates a modified form of reciprocating device for the agitators, this form being a compressed-air operated piston and cylinder.

The machine shown in assembled form in Figs. 1 and 2, comprises an open box 10 having a pulp feed 12, froth launders 13 at the sides, and a gangue overflow discharge 14. A plurality of supporting posts 15 carry horizontal rails 16 and 17 which respectively support guides 18 for the hollow stems 20 0 he aerators 32, and mountings 22 for a line shaft 23 provided with eccentrics 24 which operate through pitmen 25 pivoted at 26 to reciprocate the hollow stems 20 and the aerating agitators 32 supported thereby. Connections 28 equipped if desired with t rottling valves of shown) and air hose 30 provide for the supply of air in regulated quantities, either free air or under slight Pressure to said stem 20 through the hose 30. Each aerator-agitator 32 may be in the form of a rid or lattice-work structure as illustrated in Figs. 3 and 4, this grid being mounted on the respective hollow stem 20 through the medium of a head 33 and a flanged sleeve 34 threaded thereinto and retaining the grid.

A plate or disk valve 35 adapted to engage a seat 36 in head 33, is mounted within said head and is also adapted to rest upon spacers 37 on the sleeve 34 to permit the passage of air around said valve and into the space below the head 33 and grid 32.

As the grid 32 is rapidly reciprocated' through the line shaft 23, eccentrics 2d, pit- I beneath and beneath the head 33, with the man 25and stem 20, a considerable amount of agitation is produced even though the stroke be short. At the same time, each upstroke of the grid tends to produce a vacuum thereresult that a quant t,- of air is drawn through neeaeae the stem 20 into the space within said head. Then, upon each downstroke the plam or disk valve 35 is forced up against its seat 36 and the air is forced to mingle with the pulp is broken into finely divided form and didused by the action ofthe grid. In order to further dlstribute the air, some of the grid spaces are filled up so as to reduce the numberof air spaces near the center and insure the workin of the air out to the periphery of the gri'. The open spaces are indicated at 38 while the filled spaces are indicated at 39. In Fig. 5, a modified form of grid is disclosed wherein a plate is drilled to provide the required numher and distribution of holes 40, the holes being smaller and fewer near the center.

Box 10 is provided with a plurality of transverse partitions 42 to form individual cells A-- for the aerating agitators 32 whereby the pulp travels from one cell -A. to the next, and is positively subjected to aeration and agitation by each member 32 before it passes to the next cell. Any form of cell or pulp container in which the element 32 works may be employed.

Referring moreparticularly to Figs. 1 and 2, the ulp entersthe feed trough 12 through the le t end and gradually flows through the cells A- from one aerator 32 to another, the heavy particles being 'keptin motion by the agitation resulting from the rapid reciprocatmg movement, while the finely diffused streams of air pick up the metallic values and carry them over the sides in the form of a froth which is discharged into the launders 13, the gangue being discharged over the overflow lip 14. If a blind spot develops at any place grid are extended to reach that spot and there produce the required agitation. As above described, the reciprocating movement causes the tendency toward development of a vacuum under the grid 32 and the head 33 on the upstroke which results in sucking air past the disk valve 35, this valve closing against its seat 36 on the downstroke and confining the air. This rapid reciprocating and in any of the cells, the arms ofthe movement results inpumping ample air into the ul beneath the grid and forcing it outwar t rough the pulp in finely diffused form, which efiect 1s materially facilitated by the rapid agitation. The stroke usually is short, being ordinarily only from one to panacea the line shaft 23 by means of a pitman25' passing through guide 18 and connected by a yoke 26'to the stem The pitman has suficient flexibility to care for the throw of the eccentric as the device is reciprocated. This device is difi'erent from the aerator 32 in that a ball valve working on a seat 46 is adapted to open on the downstrok'e and close on the upstroke so that on each downstroke a quantity of pulp is forced through the hollow stem 20' and caused to overflow the top thereof. This action assists the en-' trance of pulp into the respective compartment B through the port 47 under the partition 43 and overthe overflow at the top of partition 42 as indicated at 48 into the next cell -A-. In this fashion a positive movement of the pulp through the unit is assured together with proper a itation to keep the heavy values in circulation. In or der that the heaviest gangue may work through the machine, gangue discharge ports 49' are provided below the partitions 42.

if desired, the aerators 32 and circulators 32" may be connected for reciprocation by some other means than the eccentrics, such as by air motors as indicated at 50 in Fig. 10,

where a supply or compressed air entering through pipe 52 serves to actuate the motor piston 53.

From the foregoing it will be clear that l have provided avery efilcient flotation apparatus in which the air su ply and the agitation are properly controlle only that amount or air andthat amount of agitation being furnished which are necessary forthe most efficient results. Power consumption also is under control because the grid need not have a great weight in itself and need not have a great weightof pulp above it, does not have to be deeply submerged, and does'not have and does not need. a long reciprocating stroke. Fineness of air bubbles, so essential to suecesstul flotation, is assured by the rapidit of reciprocation and the form of the gri and is thereby also under control.

I claim:

1. ln flotation apparatus, a plurality of cells arranged in series, an aerator in each cell, compartments between the cells, and agitating circulators disposed in said compartments.

2. A flotation apparatus comprising a plurality of cells arranged in series, aerators in the cells, and agitating circulators disposed between the cells to insure circulation from one cell to the next.

' 3. An ap aratus for mineral flotation comprising a p urality of cells arranged in series with c1rculation compartments therebetween,

' each of said cells being rovided with a reciprocating. device inclu mg'a combined agitater and aerator, means to reciprocate said agitator, and agitating circulators disposed m sald compartments.

4. An apparatus for mineral flotation comprising a plurality of interconnecting cells arranged in series with circulation compartments therebetween, an aerating a itator mounted in each cell, means to verticfily reci rocate said agitators, an air valve in each o said agitators to pass air on the upstroke, each of said agitators including an extensivel apertured grid for eflicient distribution of the air, the air being discharged below the grids, and agitating circulators disposed in said com artments.

5. A mineral flotation apparatus including a plurality of interconnecting cells arranged in series with circulation compartments therebetween, a reciprocative agitator including an air pump connected to discharge below the agitator mounted in each cell, means to reciprocate said agitators, and agitating circulators disposed in said compartments.

6. A mineral flotation apparatus including a plurality of interconnecting cells arranged in series with circulation compartments therebetween, a reciprocative agitator including an air pump connected to discharge below the agitator mounted in each cell, and means to reciprocate said agitators with their pumps, each of said agitators being in the form of horizontally disposed extensively apertured grids adapted for thorough distribution of air through the mineral pump to be treated, and agitating circulators disposedv in said compartments.

a plurality of interconnecting cells arrange in series with circulation compartments therebetween, a reciprocative agitator in- I eluding an air pump connected to discharge below the agitator mounted in each cell, and means to reciprocate said agitators with me their pumps, each of said air pumps including a valve to pass air on the upstroke and to close on the down stroke, and agitating circulators disposed in said compartments.

8. A mineral flotation apparatus includ-- no ing a plurality of interconnecting cells arranged in series with circulation compartments thercbetween, aeratin agitators each having an apertured grid a a ted for thorou h distribution of air, a ho low stem carare ments therebetween, a. combined agitator and pump comprising a hollow stem mounted in each'cell, a foraminous grid carried by each stem, and a valvemountcd in each stem to pass fluid in one direction between the underside of the. grids and the tops of the tator and an aerator mounted in each upon reciprocation of the grids, means reclprocate said grids successively, and agitating circuiators disposed in said compatt meats.

10. A flotation apparatus comprising a plurality of cells arranged in series with air: culation compartments therehetween, an agiif ce each of said agitators and aerators comp'ris ing a hollow stem, a grid carried thereby, and a valve cooperating with said stem to pass fluid in one direction between the underside of the grid and the top of the stem upon reciprocation of the grid, means to reciprocate the grid, each of said grids having air passages therethrough of less area at the center in any radial line than at the peripher and agitating circulators disposed in sai compartments.

In testimony whereof I afiix my signature.

HERBERT WATMUUGH PUDAN.

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